/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2008 Luis R. Rodriguez <lrodriguz@atheros.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/**
* DOC: Wireless regulatory infrastructure
*
* The usual implementation is for a driver to read a device EEPROM to
* determine which regulatory domain it should be operating under, then
* looking up the allowable channels in a driver-local table and finally
* registering those channels in the wiphy structure.
*
* Another set of compliance enforcement is for drivers to use their
* own compliance limits which can be stored on the EEPROM. The host
* driver or firmware may ensure these are used.
*
* In addition to all this we provide an extra layer of regulatory
* conformance. For drivers which do not have any regulatory
* information CRDA provides the complete regulatory solution.
* For others it provides a community effort on further restrictions
* to enhance compliance.
*
* Note: When number of rules --> infinity we will not be able to
* index on alpha2 any more, instead we'll probably have to
* rely on some SHA1 checksum of the regdomain for example.
*
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/nl80211.h>
#include <linux/platform_device.h>
#include <net/wireless.h>
#include <net/cfg80211.h>
#include "core.h"
#include "reg.h"
/*
* wiphy is set if this request's initiator is
* REGDOM_SET_BY_COUNTRY_IE or _DRIVER
*/
struct regulatory_request {
struct wiphy *wiphy;
enum reg_set_by initiator;
char alpha2[2];
};
static struct regulatory_request *last_request;
/* To trigger userspace events */
static struct platform_device *reg_pdev;
/* Keep the ordering from large to small */
static u32 supported_bandwidths[] = {
MHZ_TO_KHZ(40),
MHZ_TO_KHZ(20),
};
/* Central wireless core regulatory domains, we only need two,
* the current one and a world regulatory domain in case we have no
* information to give us an alpha2 */
static const struct ieee80211_regdomain *cfg80211_regdomain;
/* We keep a static world regulatory domain in case of the absence of CRDA */
static const struct ieee80211_regdomain world_regdom = {
.n_reg_rules = 1,
.alpha2 = "00",
.reg_rules = {
REG_RULE(2412-10, 2462+10, 40, 6, 20,
NL80211_RRF_PASSIVE_SCAN |
NL80211_RRF_NO_IBSS),
}
};
static const struct ieee80211_regdomain *cfg80211_world_regdom =
&world_regdom;
#ifdef CONFIG_WIRELESS_OLD_REGULATORY
static char *ieee80211_regdom = "US";
module_param(ieee80211_regdom, charp, 0444);
MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
/* We assume 40 MHz bandwidth for the old regulatory work.
* We make emphasis we are using the exact same frequencies
* as before */
static const struct ieee80211_regdomain us_regdom = {
.n_reg_rules = 6,
.alpha2 = "US",
.reg_rules = {
/* IEEE 802.11b/g, channels 1..11 */
REG_RULE(2412-10, 2462+10, 40, 6, 27, 0),
/* IEEE 802.11a, channel 36 */
REG_RULE(5180-10, 5180+10, 40, 6, 23, 0),
/* IEEE 802.11a, channel 40 */
REG_RULE(5200-10, 5200+10, 40, 6, 23, 0),
/* IEEE 802.11a, channel 44 */
REG_RULE(5220-10, 5220+10, 40, 6, 23, 0),
/* IEEE 802.11a, channels 48..64 */
REG_RULE(5240-10, 5320+10, 40, 6, 23, 0),
/* IEEE 802.11a, channels 149..165, outdoor */
REG_RULE(5745-10, 5825+10, 40, 6, 30, 0),
}
};
static const struct ieee80211_regdomain jp_regdom = {
.n_reg_rules = 3,
.alpha2 = "JP",
.reg_rules = {
/* IEEE 802.11b/g, channels 1..14 */
REG_RULE(2412-10, 2484+10, 40, 6, 20, 0),
/* IEEE 802.11a, channels 34..48 */
REG_RULE(5170-10, 5240+10, 40, 6, 20,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channels 52..64 */
REG_RULE(5260-10, 5320+10, 40, 6, 20,
NL80211_RRF_NO_IBSS |
NL80211_RRF_DFS),
}
};
static const struct ieee80211_regdomain eu_regdom = {
.n_reg_rules = 6,
/* This alpha2 is bogus, we leave it here just for stupid
* backward compatibility */
.alpha2 = "EU",
.reg_rules = {
/* IEEE 802.11b/g, channels 1..13 */
REG_RULE(2412-10, 2472+10, 40, 6, 20, 0),
/* IEEE 802.11a, channel 36 */
REG_RULE(5180-10, 5180+10, 40, 6, 23,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channel 40 */
REG_RULE(5200-10, 5200+10, 40, 6, 23,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channel 44 */
REG_RULE(5220-10, 5220+10, 40, 6, 23,
NL80211_RRF_PASSIVE_SCAN),
/* IEEE 802.11a, channels 48..64 */
REG_RULE(5240-10, 5320+10, 40, 6, 20,
NL80211_RRF_NO_IBSS |
NL80211_RRF_DFS),
/* IEEE 802.11a, channels 100..140 */
REG_RULE(5500-10, 5700+10, 40, 6, 30,
NL80211_RRF_NO_IBSS |
NL80211_RRF_DFS),
}
};
static const struct ieee80211_regdomain *static_regdom(char *alpha2)
{
if (alpha2[0] == 'U' && alpha2[1] == 'S')
return &us_regdom;
if (alpha2[0] == 'J' && alpha2[1] == 'P')
return &jp_regdom;
if (alpha2[0] == 'E' && alpha2[1] == 'U')
return &eu_regdom;
/* Default, as per the old rules */
return &us_regdom;
}
static bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
{
if (rd == &us_regdom || rd == &jp_regdom || rd == &eu_regdom)
return true;
return false;
}
#else
static inline bool is_old_static_regdom(const struct ieee80211_regdomain *rd)
{
return false;
}
#endif
static void reset_regdomains(void)
{
/* avoid freeing static information or freeing something twice */
if (cfg80211_regdomain == cfg80211_world_regdom)
cfg80211_regdomain = NULL;
if (cfg80211_world_regdom == &world_regdom)
cfg80211_world_regdom = NULL;
if (cfg80211_regdomain == &world_regdom)
cfg80211_regdomain = NULL;
if (is_old_static_regdom(cfg80211_regdomain))
cfg80211_regdomain = NULL;
kfree(cfg80211_regdomain);
kfree(cfg80211_world_regdom);
cfg80211_world_regdom = &world_regdom;
cfg80211_regdomain = NULL;
}
/* Dynamic world regulatory domain requested by the wireless
* core upon initialization */
static void update_world_regdomain(const struct ieee80211_regdomain *rd)
{
BUG_ON(!last_request);
reset_regdomains();
cfg80211_world_regdom = rd;
cfg80211_regdomain = rd;
}
bool is_world_regdom(const char *alpha2)
{
if (!alpha2)
return false;
if (alpha2[0] == '0' && alpha2[1] == '0')
return true;
return false;
}
static bool is_alpha2_set(const char *alpha2)
{
if (!alpha2)
return false;
if (alpha2[0] != 0 && alpha2[1] != 0)
return true;
return false;
}
static bool is_alpha_upper(char letter)
{
/* ASCII A - Z */
if (letter >= 65 && letter <= 90)
return true;
return false;
}
static bool is_unknown_alpha2(const char *alpha2)
{
if (!alpha2)
return false;
/* Special case where regulatory domain was built by driver
* but a specific alpha2 cannot be determined */
if (alpha2[0] == '9' && alpha2[1] == '9')
return true;
return false;
}
static bool is_an_alpha2(const char *alpha2)
{
if (!alpha2)
return false;
if (is_alpha_upper(alpha2[0]) && is_alpha_upper(alpha2[1]))
return true;
return false;
}
static bool alpha2_equal(const char *alpha2_x, const char *alpha2_y)
{
if (!alpha2_x || !alpha2_y)
return false;
if (alpha2_x[0] == alpha2_y[0] &&
alpha2_x[1] == alpha2_y[1])
return true;
return false;
}
static bool regdom_changed(const char *alpha2)
{
if (!cfg80211_regdomain)
return true;
if (alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
return false;
return true;
}
/* This lets us keep regulatory code which is updated on a regulatory
* basis in userspace. */
static int call_crda(const char *alpha2)
{
char country_env[9 + 2] = "COUNTRY=";
char *envp[] = {
country_env,
NULL
};
if (!is_world_regdom((char *) alpha2))
printk(KERN_INFO "cfg80211: Calling CRDA for country: %c%c\n",
alpha2[0], alpha2[1]);
else
printk(KERN_INFO "cfg80211: Calling CRDA to update world "
"regulatory domain\n");
country_env[8] = alpha2[0];
country_env[9] = alpha2[1];
return kobject_uevent_env(®_pdev->dev.kobj, KOBJ_CHANGE, envp);
}
/* Used by nl80211 before kmalloc'ing our regulatory domain */
bool reg_is_valid_request(const char *alpha2)
{
if (!last_request)
return false;
return alpha2_equal(last_request->alpha2, alpha2);
}
/* Sanity check on a regulatory rule */
static bool is_valid_reg_rule(const struct ieee80211_reg_rule *rule)
{
const struct ieee80211_freq_range *freq_range = &rule->freq_range;
u32 freq_diff;
if (freq_range->start_freq_khz == 0 || freq_range->end_freq_khz == 0)
return false;
if (freq_range->start_freq_khz > freq_range->end_freq_khz)
return false;
freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
if (freq_diff <= 0 || freq_range->max_bandwidth_khz > freq_diff)
return false;
return true;
}
static bool is_valid_rd(const struct ieee80211_regdomain *rd)
{
const struct ieee80211_reg_rule *reg_rule = NULL;
unsigned int i;
if (!rd->n_reg_rules)
return false;
for (i = 0; i < rd->n_reg_rules; i++) {
reg_rule = &rd->reg_rules[i];
if (!is_valid_reg_rule(reg_rule))
return false;
}
return true;
}
/* Returns value in KHz */
static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range,
u32 freq)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(supported_bandwidths); i++) {
u32 start_freq_khz = freq - supported_bandwidths[i]/2;
u32 end_freq_khz = freq + supported_bandwidths[i]/2;
if (start_freq_khz >= freq_range->start_freq_khz &&
end_freq_khz <= freq_range->end_freq_khz)
return supported_bandwidths[i];
}
return 0;
}
/* XXX: add support for the rest of enum nl80211_reg_rule_flags, we may
* want to just have the channel structure use these */
static u32 map_regdom_flags(u32 rd_flags)
{
u32 channel_flags = 0;
if (rd_flags & NL80211_RRF_PASSIVE_SCAN)
channel_flags |= IEEE80211_CHAN_PASSIVE_SCAN;
if (rd_flags & NL80211_RRF_NO_IBSS)
channel_flags |= IEEE80211_CHAN_NO_IBSS;
if (rd_flags & NL80211_RRF_DFS)
channel_flags |= IEEE80211_CHAN_RADAR;
return channel_flags;
}
/**
* freq_reg_info - get regulatory information for the given frequency
* @center_freq: Frequency in KHz for which we want regulatory information for
* @bandwidth: the bandwidth requirement you have in KHz, if you do not have one
* you can set this to 0. If this frequency is allowed we then set
* this value to the maximum allowed bandwidth.
* @reg_rule: the regulatory rule which we have for this frequency
*
* Use this function to get the regulatory rule for a specific frequency.
*/
static int freq_reg_info(u32 center_freq, u32 *bandwidth,
const struct ieee80211_reg_rule **reg_rule)
{
int i;
u32 max_bandwidth = 0;
if (!cfg80211_regdomain)
return -EINVAL;
for (i = 0; i < cfg80211_regdomain->n_reg_rules; i++) {
const struct ieee80211_reg_rule *rr;
const struct ieee80211_freq_range *fr = NULL;
const struct ieee80211_power_rule *pr = NULL;
rr = &cfg80211_regdomain->reg_rules[i];
fr = &rr->freq_range;
pr = &rr->power_rule;
max_bandwidth = freq_max_bandwidth(fr, center_freq);
if (max_bandwidth && *bandwidth <= max_bandwidth) {
*reg_rule = rr;
*bandwidth = max_bandwidth;
break;
}
}
return !max_bandwidth;
}
static void handle_channel(struct ieee80211_channel *chan)
{
int r;
u32 flags = chan->orig_flags;
u32 max_bandwidth = 0;
const struct ieee80211_reg_rule *reg_rule = NULL;
const struct ieee80211_power_rule *power_rule = NULL;
r = freq_reg_info(MHZ_TO_KHZ(chan->center_freq),
&max_bandwidth, ®_rule);
if (r) {
flags |= IEEE80211_CHAN_DISABLED;
chan->flags = flags;
return;
}
power_rule = ®_rule->power_rule;
chan->flags = flags | map_regdom_flags(reg_rule->flags);
chan->max_antenna_gain = min(chan->orig_mag,
(int) MBI_TO_DBI(power_rule->max_antenna_gain));
chan->max_bandwidth = KHZ_TO_MHZ(max_bandwidth);
if (chan->orig_mpwr)
chan->max_power = min(chan->orig_mpwr,
(int) MBM_TO_DBM(power_rule->max_eirp));
else
chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp);
}
static void handle_band(struct ieee80211_supported_band *sband)
{
int i;
for (i = 0; i < sband->n_channels; i++)
handle_channel(&sband->channels[i]);
}
static void update_all_wiphy_regulatory(enum reg_set_by setby)
{
struct cfg80211_registered_device *drv;
list_for_each_entry(drv, &cfg80211_drv_list, list)
wiphy_update_regulatory(&drv->wiphy, setby);
}
void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby)
{
enum ieee80211_band band;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
if (wiphy->bands[band])
handle_band(wiphy->bands[band]);
if (wiphy->reg_notifier)
wiphy->reg_notifier(wiphy, setby);
}
}
/* This has the logic which determines when a new request
* should be ignored. */
static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by,
const char *alpha2)
{
/* All initial requests are respected */
if (!last_request)
return 0;
switch (set_by) {
case REGDOM_SET_BY_INIT:
return -EINVAL;
case REGDOM_SET_BY_CORE:
/*
* Always respect new wireless core hints, should only happen
* when updating the world regulatory domain at init.
*/
return 0;
case REGDOM_SET_BY_COUNTRY_IE:
if (unlikely(!is_an_alpha2(alpha2)))
return -EINVAL;
if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
if (last_request->wiphy != wiphy) {
/*
* Two cards with two APs claiming different
* different Country IE alpha2s. We could
* intersect them, but that seems unlikely
* to be correct. Reject second one for now.
*/
if (!alpha2_equal(alpha2,
cfg80211_regdomain->alpha2))
return -EOPNOTSUPP;
return -EALREADY;
}
/* Two consecutive Country IE hints on the same wiphy */
if (!alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
return 0;
return -EALREADY;
}
/*
* Ignore Country IE hints for now, need to think about
* what we need to do to support multi-domain operation.
*/
return -EOPNOTSUPP;
case REGDOM_SET_BY_DRIVER:
if (last_request->initiator == REGDOM_SET_BY_DRIVER)
return -EALREADY;
return 0;
case REGDOM_SET_BY_USER:
/*
* If the user wants to override the AP's hint, we may
* need to follow both and use the intersection. For now,
* reject any such attempt (but we don't support country
* IEs right now anyway.)
*/
if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
return -EOPNOTSUPP;
return 0;
}
return -EINVAL;
}
/* Caller must hold &cfg80211_drv_mutex */
int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by,
const char *alpha2)
{
struct regulatory_request *request;
int r = 0;
r = ignore_request(wiphy, set_by, alpha2);
if (r)
return r;
switch (set_by) {
case REGDOM_SET_BY_CORE:
case REGDOM_SET_BY_COUNTRY_IE:
case REGDOM_SET_BY_DRIVER:
case REGDOM_SET_BY_USER:
request = kzalloc(sizeof(struct regulatory_request),
GFP_KERNEL);
if (!request)
return -ENOMEM;
request->alpha2[0] = alpha2[0];
request->alpha2[1] = alpha2[1];
request->initiator = set_by;
request->wiphy = wiphy;
kfree(last_request);
last_request = request;
r = call_crda(alpha2);
#ifndef CONFIG_WIRELESS_OLD_REGULATORY
if (r)
printk(KERN_ERR "cfg80211: Failed calling CRDA\n");
#endif
break;
default:
r = -ENOTSUPP;
break;
}
return r;
}
void regulatory_hint(struct wiphy *wiphy, const char *alpha2)
{
BUG_ON(!alpha2);
mutex_lock(&cfg80211_drv_mutex);
__regulatory_hint(wiphy, REGDOM_SET_BY_DRIVER, alpha2);
mutex_unlock(&cfg80211_drv_mutex);
}
EXPORT_SYMBOL(regulatory_hint);
static void print_rd_rules(const struct ieee80211_regdomain *rd)
{
unsigned int i;
const struct ieee80211_reg_rule *reg_rule = NULL;
const struct ieee80211_freq_range *freq_range = NULL;
const struct ieee80211_power_rule *power_rule = NULL;
printk(KERN_INFO "\t(start_freq - end_freq @ bandwidth), "
"(max_antenna_gain, max_eirp)\n");
for (i = 0; i < rd->n_reg_rules; i++) {
reg_rule = &rd->reg_rules[i];
freq_range = ®_rule->freq_range;
power_rule = ®_rule->power_rule;
/* There may not be documentation for max antenna gain
* in certain regions */
if (power_rule->max_antenna_gain)
printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
"(%d mBi, %d mBm)\n",
freq_range->start_freq_khz,
freq_range->end_freq_khz,
freq_range->max_bandwidth_khz,
power_rule->max_antenna_gain,
power_rule->max_eirp);
else
printk(KERN_INFO "\t(%d KHz - %d KHz @ %d KHz), "
"(N/A, %d mBm)\n",
freq_range->start_freq_khz,
freq_range->end_freq_khz,
freq_range->max_bandwidth_khz,
power_rule->max_eirp);
}
}
static void print_regdomain(const struct ieee80211_regdomain *rd)
{
if (is_world_regdom(rd->alpha2))
printk(KERN_INFO "cfg80211: World regulatory "
"domain updated:\n");
else {
if (is_unknown_alpha2(rd->alpha2))
printk(KERN_INFO "cfg80211: Regulatory domain "
"changed to driver built-in settings "
"(unknown country)\n");
else
printk(KERN_INFO "cfg80211: Regulatory domain "
"changed to country: %c%c\n",
rd->alpha2[0], rd->alpha2[1]);
}
print_rd_rules(rd);
}
static void print_regdomain_info(const struct ieee80211_regdomain *rd)
{
printk(KERN_INFO "cfg80211: Regulatory domain: %c%c\n",
rd->alpha2[0], rd->alpha2[1]);
print_rd_rules(rd);
}
/* Takes ownership of rd only if it doesn't fail */
static int __set_regdom(const struct ieee80211_regdomain *rd)
{
/* Some basic sanity checks first */
if (is_world_regdom(rd->alpha2)) {
if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
return -EINVAL;
update_world_regdomain(rd);
return 0;
}
if (!is_alpha2_set(rd->alpha2) && !is_an_alpha2(rd->alpha2) &&
!is_unknown_alpha2(rd->alpha2))
return -EINVAL;
if (!last_request)
return -EINVAL;
/* allow overriding the static definitions if CRDA is present */
if (!is_old_static_regdom(cfg80211_regdomain) &&
!regdom_changed(rd->alpha2))
return -EINVAL;
/* Now lets set the regulatory domain, update all driver channels
* and finally inform them of what we have done, in case they want
* to review or adjust their own settings based on their own
* internal EEPROM data */
if (WARN_ON(!reg_is_valid_request(rd->alpha2)))
return -EINVAL;
reset_regdomains();
/* Country IE parsing coming soon */
switch (last_request->initiator) {
case REGDOM_SET_BY_CORE:
case REGDOM_SET_BY_DRIVER:
case REGDOM_SET_BY_USER:
if (!is_valid_rd(rd)) {
printk(KERN_ERR "cfg80211: Invalid "
"regulatory domain detected:\n");
print_regdomain_info(rd);
return -EINVAL;
}
break;
case REGDOM_SET_BY_COUNTRY_IE: /* Not yet */
WARN_ON(1);
default:
return -EOPNOTSUPP;
}
/* Tada! */
cfg80211_regdomain = rd;
return 0;
}
/* Use this call to set the current regulatory domain. Conflicts with
* multiple drivers can be ironed out later. Caller must've already
* kmalloc'd the rd structure. Caller must hold cfg80211_drv_mutex */
int set_regdom(const struct ieee80211_regdomain *rd)
{
int r;
/* Note that this doesn't update the wiphys, this is done below */
r = __set_regdom(rd);
if (r) {
kfree(rd);
return r;
}
/* This would make this whole thing pointless */
BUG_ON(rd != cfg80211_regdomain);
/* update all wiphys now with the new established regulatory domain */
update_all_wiphy_regulatory(last_request->initiator);
print_regdomain(rd);
return r;
}
int regulatory_init(void)
{
int err;
reg_pdev = platform_device_register_simple("regulatory", 0, NULL, 0);
if (IS_ERR(reg_pdev))
return PTR_ERR(reg_pdev);
#ifdef CONFIG_WIRELESS_OLD_REGULATORY
cfg80211_regdomain = static_regdom(ieee80211_regdom);
printk(KERN_INFO "cfg80211: Using static regulatory domain info\n");
print_regdomain_info(cfg80211_regdomain);
/* The old code still requests for a new regdomain and if
* you have CRDA you get it updated, otherwise you get
* stuck with the static values. We ignore "EU" code as
* that is not a valid ISO / IEC 3166 alpha2 */
if (ieee80211_regdom[0] != 'E' || ieee80211_regdom[1] != 'U')
err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE,
ieee80211_regdom);
#else
cfg80211_regdomain = cfg80211_world_regdom;
err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE, "00");
if (err)
printk(KERN_ERR "cfg80211: calling CRDA failed - "
"unable to update world regulatory domain, "
"using static definition\n");
#endif
return 0;
}
void regulatory_exit(void)
{
mutex_lock(&cfg80211_drv_mutex);
reset_regdomains();
kfree(last_request);
platform_device_unregister(reg_pdev);
mutex_unlock(&cfg80211_drv_mutex);
}